Ravens can tell when a hidden potential competitor is spying on them, according to a new study from the Universities or Vienna and Houston. Researchers say this demonstrates that the birds (Corvus corax) have a human-like ability to think abstractly – to surmise what might be going on in the mind of another.

A six-month long study on 10 ravens raised in captivity revealed the famously intelligent birds take extra care to hide their catches of food if they suspect their movements are being monitored by another raven – even when the second bird is not really there, according to University of Vienna researchers news release.

For the experiment, the birds were placed in adjoining rooms divided by a window that was intentionally left uncovered, so one raven could watch while the other was given food to hide.

Researchers then covered the window, leaving only a small peephole that the birds were taught they could see and be seen through.

When the peephole was left open, the ravens were extra cautious about hiding their food. But when the peephole was closed, the birds easily determined they could not be spied upon and relaxed. This was the case even though they could still hear other ravens behind the glass. 

Previous research, mainly with chimpanzees and other species closely tied to humans, has shown that animals can understand what others see, but only by monitoring an individual's head or eye movements – what scientists call "gaze cues." However, even without those cues, the ravens proved they understood when someone could be watching and adjusted their behaviors accordingly.

"This strongly suggests that ravens make generalizations based on their experience, and do not merely interpret and respond to behavioral cues from other birds," lead author Thomas Bugnyar, a professor at the University of Vienna and a leading expert on social cognition in animals, said in a statement.

The next step, researchers say, is to test what other animals are capable of the kind of abstraction assessed in the peephole test.

The study's findings were recently published in the journal Nature Communications

Related Articles 

Ravens Cooperate With Surprising Intelligence, But Only With Friends

Crows Understand Death And Threat Of It From Predators

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Samantha on Twitter @Sam_Ashley13